1. Field of the Invention
The present invention relates to a baby carriage, and more particularly, it relates to an improvement in a mechanism for changing the angle of inclination of a backrest portion of a seat provided in a baby carriage.
2. Description of the Background Art
At present, a baby carriage generally comprises a seat. In such a baby carriage, the angle of inclination of a backrest portion is generally changeable. Such a baby carriage must be reduced in weight, and hence it is desirable to simplify the structure of a mechanism for changing the angle of inclination of the backrest portion.
For example, Japanese Utility Model Application Laying-Open No. 3-8968 (1991) in the name of the assignee describes a mechanism for changing the angle of inclination of a backrest portion, which can be implemented in a simple structure. In a baby carriage described in this Japanese Laying-Open Publication, a belt assembly is arranged on a back side of the backrest portion for supporting the same, so that the angle of inclination of the backrest portion can be changed by adjusting the length of the belt assembly.
The length of the belt assembly is adjusted in the following manner: The belt assembly comprises a first belt having an end which is coupled to one of two push rods, a second belt having an end which is coupled to the other push rod, and a buckle which is coupled to another end of the first belt and provided with a belt passage for passing the second belt therethrough. The buckle is rotatably provided with a stopper having a cam surface which frictionally engages with the second belt positioned in the belt passage, when the rotatable stopper is brought into a prescribed rotational position for inhibiting the buckle and the second belt from relative movement.
The aforementioned mechanism for changing the angle of inclination of the backrest portion is simple in structure and operation, and adapted to fix or secure the second belt which is positioned in the belt passage of the buckle by frictional engagement, whereby the length of the belt assembly can advantageously be adjusted in a stepless manner. Thus, the angle of inclination of the backrest portion can be adjusted in a stepless manner.
However, although the aforementioned frictional engagement for fixing the second belt advantageously enables stepless adjustment, fixation of the second belt is inferior in reliability. In other words, the second belt cannot be reliably fixed or secured when the frictionally engaging portion becomes worn.